function bookcheck(){
	var firstName = document.getElementById('firstName').value;
	var no = document.getElementById('no').value;
	var name = document.getElementById('name').value;
	var author = document.getElementById('author').value;
	var count = document.getElementById('count').value;
	if(firstName==""){
		var date = new Date();
		alert("书类不能为空，请选择书类！");
		return false;
	}
	if(no==""){
		alert("编号不能为空，请输入编号！");
		return false;
	}
	if(name==""){
		alert("书名不能为空，请输入书名！");
		return false;
	}
	if(author==""){
		alert("作者不能为空，请输入作者！");
		return false;
	}
	if(count==""||(isNaN(count))){
		alert("数量不能为空且必须为数字，请输入数量！");
		return false;
	}
}